1. Field of Invention
This invention relates to radio frequency (RF) signal pulse oscillators, and more particularly to mode-locked, pulsed RF frequency operation of a surface acoustic wave oscillator.
2. Description of the Prior Art
Pulsed RF oscillators for providing phase coherent RF signal pulses are known in the art, and generally provide pulsed RF operation through periodic interruption of a continuous wave RF signal rather than frequency mode-locking within the regenerative RF signal path. An early regenerative type pulse generator for use in the microwave frequency range, which exhibited self mode-locking characteristics was first disclosed by C. C. Cutler in an article "The Regenerative Pulse Generator", Proceedings of the IEEE, February 1955, pages 140-148, and patented under U.S. Pat. No. 2,617,930 issued on Nov. 11, 1952. Laser configurations have been devised which also demonstrated mode-locked oscillation characteristics, as discussed by L. W. Hargrove, R. L. Fork, and M. A. Pollack, in an article "Locking of He-Ne Laser Modes Introduced by Synchronous Intercavity Modulation", Applied Physics Letters, Vol. 5, 1964, pages 4-5 and by A. J. DeMaria, D. A. Stetser and W. H. Glenn, in an article "Ultrashort Light Pulses", Science Magazine, Vol. 156, June 1967, pages 1557-1568, which is the subject of U.S. Pat. No. 3,636,474 entitled "Ultrashort Optical Pulse Generation Utilizing Laser Pumped Lasers", issued on Jan. 18, 1972.